Extruder for a three-dimensional printer



FIG. 1 is a front, right side perspective view of an extruder for a three-dimensional printer;

FIG. 2 is a bottom view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof

The broken lines immediately adjacent to the claim depict the bounds of the claimed design, while all other broken lines are directed to environment. The broken lines form no part of the claimed design. The attached Appendix includes additional images and drawings of the extruder for a three-dimensional printer. 

CLAIM The ornamental design for an extruder for a three-dimensional printer, as shown and described. 